Color control for electric bread toasters



Sept. 2, 1952 H.L. OLSON ET'AL COLOR CONTROL FOR ELECTRIC BREAD TOASTERS 2 SHEETS-SHEET 1 Filed Dec. 23, 1949 lllilllllmllllllll INVENTORS HENRY L. OLsoNAND ROBERT A. MILLER AT T O R N E Y S Patented Sept. 2, 1952 UNITED STATES PATENT OFFICE COLOR CONTROL FOR ELECTRIC BREAD TOASTERS Henry L. Olson and Robert A. Miller, Grand Haven, Mich., assignors to Camfield Manufacturing Company, Grand Haven, Mich., a corporation of Michigan Application December 23, 1949, Serial No. 134,668

13 Claims. 1

Our invention relates to bread toasters and particularly to a color control device for electric bread toasters. The present application is related to Serial No. 7,629, filed February 11, 1948 and to Serial No. 143,723, filed February 11, 1950, both having the same assignee as the present application.

An object of the invention resides in providing a control device which may be operated from either end of the toaster.

Another object of the invention resides in providing the control device with a revoluble adjusting member having a pinion rotatable therewith and with a lever carrying a rack engageable with said pinion.

A still further object of the invention resides in pivoting said lever for movement about a vertical pivot near the center of the toaster and in connecting said rack to said lever for transverse movement relative to the toaster.

Other objects of the invention reside in the novel combination and arrangement of parts and in the details of construction hereinafter illustrated and/or described.

The bread toaster disclosed in this application consists of a case A in which is disposed a framework B. The framework B and associated parts provides two vertical bread ovens C into which the bread may be placed through suitable openings in the upper portion of the case A. Within the framework B is disposed two vertically movable bread racks D which support the bread within the ovens C and which are spring biased to non-toasting position. A timing mechanism E is adapted to determine the cooking period and operates to release a latching device F whereupon the bread racks are returned to normal position at the end of the cooking period. Associated with the timing device E is a color control device G adapted to vary the length of the toasting period. This device includes a vertical shaft having a pinion mounted thereon. Beneath the framework B is a longitudinally extending lever pivoted intermediate the ends of the frame for swinging movement in a horizontal plane. This lever extends beyond the ends of the toaster and is provided with knobs by means of which the lever may be manipulated from either end of the toaster. A rack meshes with said pinion and a connector disposed between said rack and lever serves to reciprocate said rack upon swinging of the lever to rotate said shaft and adjust the color control device.

In the drawings:

Fig. 1 is a plan sectional View of a portion 2 of an electric toaster illustrating an embodiment of my invention and taken substantially on line l| of Fig. 2.

Fig. 2 is a longitudinal elevational sectional View of the toaster taken substantially on line 2-2 of Fig. 1.

Fig. 3 is a fragmentary cross sectional View taken substantially on line 33 of Fig. 1.

Fig. 4 is a fragmentary cross sectional view taken substantially on line 4-4 of Fig. 1.

The case A of our invention as best shown in Fig. 2 consists of a lower case section If) which extends about the entire toaster and which has ends II and sides [2. The lowermost part of the case section In has flanges 13 extending inwardly therefrom and on which the toaster mechanism rests. The upper part of the section 10 has an offset l4 formed in the same and which provides a recess l1. overlying the section IE) is an upper case section l5. This case section is dome-shaped in form and the lower marginal portion l6 of said case section is received within the recess I! formed by the offset l4. Screws [8 extending through the lowermost marginal portion 18 and threaded into the offset 14 hold the parts of the case assembled. Attached to the ends I l of case section l2 are end pieces [9 which are preferably constructed of some plastic material and which form ornaments for dressing up the case structure. These end pieces have body portions 2| which overlie the ends ll of the case and are secured thereto by means of screws 22. These end pieces furthermore have feet 23 which are disposed beneath the section Hi and support the entire toaster above the table on which it rests to provide ventilation and retard the transfer of heat to the table. The section [5 of case A is constructed with openings 38 which register with the bread ovens C and through which the bread may be inserted into said ovens and placed upon the bread racks D.

Within the case A is located the framework B which supports the mechanism of the invention. This framework consists of a frame 24, of inverted U-shaped form, having an upper longitudinally extending frame member 25 and two vertically extending frame members 26 and 21 connected thereto. The frame members 26 and 21 have flanges 23 projecting outwardly therefrom and lying in a common plane. These flanges rest upon the flanges l3 and support the frame structure through the lower case section l0. Screws 20 hold the framework B attached to the flanges it of case A.

Within the framework B is provided four heating elements 29, 3|, 32 and 33 which consists of sheets of mica 34 on which are wound suitable resistors 35. These heating elements in conjunction with the vertical frame members 26 and 21, form the two bread ovens C which are disposed between the heating elements 29 and 3| and between the heating elements 32 and 33. The heating elements 3| and 32 are also separated from one another to form a space 36 therebetween and in which certain of the mechanism of the invention is disposed. For supporting the heating elements 29, 3|, 32 and 33 two threaded rods 3'! are employed which extend through said heating elements. hold the heating elements mounted thereon. The heating elements 29, 3|, 32 and 33 have reinforcing strips 44 secured to the upper and lower ends of the same and which also serve for attachment of guide wires 45. These guide wires are spaced from the resistors 35 and prevent the toast from coming in direct contact therewith and burning.

For supporting the toast within the oven C the two bread racks D are employed. These bread racks consist of elongated bars 43 which have lugs 39 projecting outwardly therefrom and on which the slices of bread may rest. These bars extend through slots 41 in the vertical frame members 26 and 21 and. are guided for. vertical movementtherein. One end'of each of. said bars has an arm 48 bent outwardly therefrom and which terminates in a lug 49: The lugs 49 straddle. two levers 52 and 53 and are pivotally connected thereto by means of rivets 54.

The lever 52 is pivoted to anupright .55 by means .of a rivet 62. This upright is secured to the frame B in the followingmanner: The upper end ofsaid upright has a finger 53 which extends over the horizontal frame member- 25; and is formed with a lug which projects downwardly through said frame-member. The lower end of the upright 55 .has a fiange58 projecting outwardly therefrom which is secured-by means of a rivet 59 to the flange 23 of frame member ZI'of frame 24. Another lever 6| hereinafter referred to as a rack lever is also pivoted to the upright 55Vby means of a rivet 53 and extends-completely through the frame 24 and througha slot 64 in one of the ends II of the case section If} and in the overlyingend piece IS. This lever forms the operating member by means of which the bread racks D aremoved into toasting position and by means of which the said bread racks may be subsequently released. The lever 6| has attached to it a knob 65 by which said lever may be depressed. Extending between the lever 52 and the lever SI is abell crank 66 which has one long arm 67 pivoted to the lever IS'I by means of a screw 58. The said lever has a short arm fie-which is pivoted to the lever 52 by means of a screw II. Lever 53 is pivoted to the bell crank 36 bymeans of a rivet I2. Below the lever 6| is another lever 13. This lever'extends completely through the frame 24 .and its innermost end is formed with an upstanding arm I'4. This arm is pivoted by means of a rivet I5 to a bracket i5 secured to the vertical frame member 26. The said lever has an offset II at its opposite end and which terminates in an extension ":8 projecting through a slot 19 in the end II of case A and in the end member I9 overlyingsaid end. A knob 35 is attached to the projecting end. of the said lever. The leversBI and 13 are connected together intermediate their ends by means of a link 82 which is pivoted to said levers by screws 83 and 84. The levers 52, 53, BI and I3 all operate inslots 85 formed in the two vertical frame members 25 Nuts 38 screwed on said rods and 2?. The ends of both of the levers 52 and BI project outwardly beyond the vertical frame member 2?. These ends of said levers have attached to them a tension coil spring I33 which has its ends E34 hooked into holes I and I03 in the said. levers. The end Id? of the lever 52 projects outwardly beyond the upright an appreciable amount so that considerable movement is given to the lever 52 tending to urge the said lever upwardly and to move the bread racks D into non-toasting position.

The timing mechanism E of the invention is of the type disclosed in the patent to R. Sardeson, 2,365,909, issued December 26, 1944. This timing mechanism includes a strip of bimetal 86 which is mounted for reciprocating movement in a guide 81. Guide 8'! is mounted on an end plate 88 forming part of the framework B. The end plate 88 has a foot 83 which rests upon and is attached to the flange 23 of frame member 26 by means of a screw 9|. The upper end of the said end plate is held in proper relation with the vertical frame members 26 by means of a spacer 92. The ends of said spacer are secured tothe plate Bil-and to the-verticalframe member 23.

The guide-8! is constructed from sheet metal and is formed to provide a bottom I4'l and end walls I48 and I49 extending upwardly therefrom. Issuing from the end wall I48 are cars I5I'. -A pintle I52 extends through these ears and'is secured to the plate 88 and-frame-membe1'26 and supports the guide 81 for swinging movement in an upand down direction. The end walls I48 and I49 have openings I53 in them and through which the strip of bimetal 33 extends and in which the bimetal is guided for longitudinal movement. p r

The color-control mechanism is constructed as follows: The end-wall I43 of guide 8'! has an arm I54 extending upwardly therefrom and which terminates in a bracket I55. Issuing laterally from the end plate 88 is an arm I56 which has formed on the sametwo spaced ears I51. These ears are threaded to receive a screw I 58 the upper end of which engages the bracket I55. This screw operates as a shaft which when rotated raisesand lowers the-guide 87 to vary the timing of the timing mechanism E as will be hereinafter more fully explained. I

For: operating the screw I58 the following construction is employed. Mounted on the said screw below the ears I5? is a pinion I59. This pinion is threaded to screw on the screw I58 and the fit between the threads of said pinion and screw are tight enough so that when the pinionis rotated a drive is effected for rotating said screw. The fit between the threads on the screw I58 and those-in the ears I5? is sufficiently free to allow of rotating the screw I58 by rotating pinion I53. A screw-driver slot I14 in screw I58'permits of rotating said screw independently of pinion I59. Meshing with the pinion I59 is a rack IBI which extends transversely of the'toaster frame B. This rack is held in engagement with thepinion I 59 by means of a U-shaped keeper I32 which straddles the pinion I59 and which is threaded to screw on the screwI 58. This keeper has a portion I63 adapted to engage the back of the rack I BI and to restrain movement of said rack away from the pinion I59. The rack |6I is operated by means of a lever I34 which extends throughout the length of the toaster and which is disposed below the frame 24. Extending between the two end plates 23 and 21 and secured thereto are two longitudinal frame members I which have inwardly turned flanges I65. ,A cross bar I51 extends between the longitudinal frame members I65 and below the flanges I66 and is attached to said flanges by means of rivets I68. The lever I64 is pivoted at the center of the same to the cross bar I61 by means of a bolt I99 which extends through said lever and cross bar. The lever I64 extends through slots I1I in the ends II of lower case section I0 and the end pieces I9 and has attached to its ends knobs I12 by means of which said lever may be swung from side to side. Mounted on the lever IE4 is a post I13 which extends upwardly therefrom and which passes through and is movable along a transverse arcuate slot I14 formed in the flange 28 of end plate 26. A screw I15 passes through the end of rack [GI and is screwed into the end of said post and serves to pivotally attach the rack to said post.

The timing mechanism E further includes a shaft 94 on which is a gear segment 95 which is adapted to cooperate with a rack 90 formed on the strip of bimetal 86 by means of spaced openings 96. The shaft 94 is secured to the plate 88. The gear segment 95 has attached to it a section 91 of a ratchet wheel, the teeth of which cooperate with a catch 98. Catch 98 is pivoted on a pintle 99 which is also attached to the plate 88. The said catch includes a finger I9I which rests on the bimetal and which is adapted to be raised to disengage the catch 98 from the section 91 of the ratchet wheel and release the gear segment 95, one tooth at a time. A spring I99 secured to the catch 98 and to the plate 88 urges the finger IIII against the strip of bimetal 95.

The bimetal strip 89 is heated by means of a heater I92 disposed within the guide 81. This heater is mounted on an insulating support I31 attached to the plate 88. It will readily be comprehended that the rate of heating of the bimetal determines the length of time required for the operation of the timing mechanism E for each cooking period.

The latching device F includes a U-shaped arm I98 hereinafter referred to as a catch arm which has spaced flanges I99 and I I I. This arm is pivotally supported on the spacer 92 which is in the form of a rod and which extends through the two flanges I99 and III. A torsion spring II 2 encircles the spacer 92 between the flanges I99 and II I and is attached to flange I99 and to the plate 88 to cause said arm to swing normally upwardly as shown in Fig. 4.

The arm I99 has pivoted to the flange I99- thereof by means of a rivet H8 a depending latch I I9. Latch I I9 has a catch I2I at the lower end of the same which is formed with a surface I45 adapted to engage a corresponding surface I46 on a catch engaging member I22. This catch engaging member forms part of a bar I23 which is secured to the gear segment 95 by means of rivets I24. Pivotally connected to the latch H9 by means of a rivet I28 is a depending link I29 which forms a connector between the latch H9 and the lever SI. This link is constructed with spaced fingers I3I and I32 at its lower end. These fingers straddle the lever BI and when the said lever is moved downwardly the said link imparts to the latch II9 downward movement.

For resetting the timing device E link I29 is formed with a shoulder I33. This shoulder is adapted to engage a lug I34 on the bar I23 and to rotate the gear segment 95 in a direction opposite to that resulting from the operation of the timing mechanism E, thus resetting the timing mechanism.

The energization of the heaters 29, 3I, 32 and 33 is procured through a switch mechanism 49 which includes fixed contacts I35 and a movable contact member I3E. The contacts I35 are mounted on the insulating support I31 previously referred to and which is attached to the plate 38. The contact member I36 is secured to the end of a spring I39 which is also attached to the plate 88 by means of screws I4 I. A cam follower M2 secured to the lever GI engages a cam I43 on the spring I39 and moves the contact member I33 into engagement with the contacts I35.

The operation of the invention is as follows: In normal position the parts are arranged as shown in Figs. 2, 3 and 4. When lever 9i is depressed latch H9 is moved downwardly and catch I2I is brought into engagement with catch engaging member I22. Spring I93 moves lever 52 and simultaneously lever SI upwardly and said lever through link I29, and catch II9 energizes the timing mechanism E. The timing mechanism now commences to function, the strip of bimetal 89 bowing in the usual manner to disengage catch 99 and allow the gear segment and ratchet segment 91 to rotate one tooth at a time. As said gear segment 95 rotates the angularity of the surface I 39 of bar I23 changes until the catch I2I slips off from the catch engaging member I22 and releases the bread racks D. At the outset initial adjustment of the color control device is procured by rotating screw I58 by means of a screw driver inserted through an enlargement I16 of the slot I16 in flange 29 of end wall 29 and engaging the screwdriver slot I1 4. The screw I58 may be turned while the lever IE4 is held from movement by forcing slippage between said screw and the pinion I59. Raising screw L38 swings the guide 81 upwardly which disengages the catch 98 from the teeth of ratchet segment 91. This reduces the amount of bowing of the strip of bimetal 36 requisite for releasing a tooth of said ratchet segment and correspondingly the length of the cooking period. The reverse movement of screw I58 produces the 0ppcsite results. Thereafter further adjustment may be made by shifting lever I84 from side to side. In such case the rack IGI is moved which rotates screw I53 through pinion I59 to procure the requisite timing of the mechanism E to give the desired color to the toast.

The advantages of the invention are manifest. The color of the toast can be controlled from either end of the toaster by movement of the color adjusting lever in the same direction with reference to either end of the toaster. The movement of the color adjusting lever is diiferent from that of the operating lever so that no confusion results. In addition the knobs for the color control lever are disposed at the lowermost portion of the toaster Where the same are out of the way when operating the operating lever. The invention is simple in construction and positive in operation and utilizes relatively inexpensive parts.

Changes in the specific form or" our invention, as herein described, may be made within the scope of what is claimed without departing from the spirit of our invention.

Having described our invention, what we claim as new and desire to protect by Letters Patent is:

1. In a bread toaster a frame, a timing mechanism at one end of the frame including a rotatable threaded shaft adapted upon rotation to vary the timing period, tapped bearings carried by said frame and supporting said shaft for rotational and longitudinal movement, a nut on said shaft frictionally engaging the same for rotating the shaft, operating means for rotating said nut, and means for rotating said shaft relative to said nut.

*2. In a bread toaster a frame, a timing mechanism at one end of the frame including a revoluble adjusting member adapted upon rotation to vary the timing period, a pinion rotatable with said revoluble member, a lever extending longitudinally of said frame and pivoted intermediate the ends of the frame and movable transversely of the frame at the ends of the frame, a transversely extending rack meshing with said pinion, a connector between said rack and lever and a keeper engageable with said rack for holding said rack in mesh with said opinion.

3. In a bread toaster a frame, a timing mechanism at one end of the frame including a revoluble adjusting member having a vertical axis adapted upon rotation to vary the timing period, a pinion rotatable with said revoluble member, a lever extending longitudinally of said frame, pivot means for said lever disposed intermediate the ends of the frame and having a vertical axis, said lever swinging in a horizontal plane, a rack meshing with said pinion and disposed in a horizontal plane, a connector between said lever and rack and a keeper engageable with said rack for holding said rack in mesh with said pinion.

4. In a bread toaster a frame, a timing mechanism at one end of the frame including a revoluble adjusting member having a vertical axis adapted upon rotation to vary the timing period, a pinion rotatable with said revoluble member,

a lever extending longitudinally of said frame,

pivot means for said lever disposed intermediate the, ends of the frame and having a vertical axis, said lever swinging in a horizontal plane, a rack meshing with said pinion and disposed in a horizontal plane, pivot means between said lever and rack and having a vertical axis and a keeper engageable with said rack to hold the rack in mesh with said pinion.

5. In a bread toaster a frame, a timing mechanism at one end of the frame including a revoluble adjusting member having a vertical axis adapted upon rotation to vary the timing period, a pinion rotatable with said revoluble member, a lever extending longitudinally of said frame, pivot means for said lever disposed intermediate the ends of the frame and having a vertical axis, said lever swinging in a horizontal plane, a rack meshing with said pinion and disposed in a horizontal plane, a post attached to said lever, said rack being pivoted to said post for swinging movement about a vertical axis and a keeper engageable with said rack to hold the rack in mesh with said pinion.

6. In a toaster a frame comprising end plates and flanges extending outwardly therefrom at the lowermost ends of the same, a support extending across said frame near the bottom thereof, a timing mechanism disposed adjacent one of said end plates and disposed above the flange issuing therefrom, said timing mechanism including a revoluble member having a vertical axis and disposed above said flange and adapted upon rotation to vary the timing period, a pinion rotatable with said revoluble member and disposed above said flange a lever extending l-ongitudinally of said frame, pivot means for said lever disposed intermediate the ends of the frame and having a vertical axis, said lever swinging in a horizontal plane, a rack meshing with said pinion and disposed in a horizontal plane, saidrack being disposed above said flange, said flange having a transverse slot therein below said rack, a post mounted on said lever and extending through and movable along said slot, pivot means between said rack and post and a keeper engageable with said rack and holding said rack in mesh with said pinion.

7. In a bread toaster a frame, a timing mechanism at one end of the frame including a vertical shaft adapted upon rotation to vary the timing period, a pinion mounted on said shaft, a lever extending longitudinally of said frame and pivoted intermediate the ends of the frame and movable transversely of the frame in a horizontal plane at the ends of the frame, a rack meshing with said pinion and extending transversely of the frame, pivot means between said lever and rack, and a keeper pivoted on said ,shaft and engageable with said rack for holding said rack in mesh with said pinion.

8. In a bread toaster a frame, a timing mechanism at one end of the frame including a vertical shaft adapted upon rotation to vary the timing period, bearings for said shaft carried by said frame, a pinion mounted on said shaft, a lever extending longitudinally of said frame and pivoted intermediate the ends of the frame and movable transversely of the frame in a horizontal plane at the ends of the frame, a rack meshing with said pinion and extending transversely of the frame, pivot means between said lever and rack and a yoke pivoted on said shaft and embracing said pinion and rack, said yoke being engageable with rack to. hold the rack in mesh with said pinion.

9. In combination, a frame comprising vertically extending end plates and flanges extending outwardly therefrom, a bread toasting oven disposed within said frame, heating means therefor, a timing mechanism disposed adjacent one of said end plates and including a revoluble member having a vertical axis disposed above the flange on said end plate and adapted upon rotation to vary the timing period, an electric switch actuated by said timing mechanism and controlling the energization and deenergization ofsaid heating means, a pinion rotatable with said revoluble member and disposed above said flange, a lever extending longitudinally of said frame and disposed below said flanges, pivot means acting between saidlever and frame and disposed intermediate the end plates of said frame and guiding said lever for movement in a substantially horizontal plane, a rack meshing with said pinion and disposed in a horizontal plane, said rack being disposed above said flange, said flange having a transverse slot therein below said rack, a post mounted on said lever and extending through and movable along said slot, pivot means between said rack and post and a keeper engageable withsaid rack and holding said rack in mesh with said pinion.

10. In combination, a frame comprising vertically extendin end frame members, a bread toasting oven disposed within said frame, heating means therefor, a timing mechanism disposed adjacent one of said end frame members and including a revoluble member having a vertical axis, and adapted on rotation to vary the timing period, an electric switch actuated by said timing mechanism and controlling the energization and deenergization of said heating means, a pinion rotatable with said revoluble member, a lever extending longitudinally of said frame and disposed below said bread toasting oven, pivot means having a vertical axis acting between said lever and frame and disposed intermediate the end members of said frame and guiding said lever for movement in a substantially horizontal plane, manual operating members disposed one on each end of said lever and accessible at the ends of the frame, a rack meshing with said pinion and disposed in a horizontal plane, pivot means disposed between said rack and said lever and causing longitudinal movement of said rack upon swinging of said lever, and a keeper engageable with said rack and holding said rack in mesh with said pinion.

11. In combination, a frame comprising vertically extending end frame members, a bread toasting oven disposed within said frame, heating means therefor, a timing mechanism disposed adjacent one of said end frame members and including a shaft having a vertical axis, and adapted on rotation to vary the timing period, an electric switch actuated by said timing mechanism and controlling the energization and deenergization of said heating means, a pinion rotatable with said shaft, a lever extendin longitudinally of said frame and disposed below said bread toasting oven, pivot means having a vertical axis acting between said lever and frame and disposed intermediate the end members of said frame and guiding said lever for movement in a substantially horizontal plane, manual operating members disposed one on each end of said lever and accessible at the ends of the frame, a rack meshing with said pinion and disposed in a horizontal plane, pivotmeans disposed between said rack and said lever and causing longitudinal movement of said rack upon swinging of said lever, and a yoke having arms pivoted on said shaft and embracing said rack and pinion, said yoke engaging said rack and holding the rack in mesh with said pinion.

12. In combination a frame, a case having ends enclosing said frame and forming with said frame adjacent one end thereof an end compartment, a timing mechanism carried by said fram and mounted in said end compartment, said timing mechanism including a revoluble member having a substantially vertical axis and adapted upon rotation to vary the timing period, a pinion rotatable with said revoluble member, a lever disposed below said frame and extending from end to end of said case, pivot means for said lever having a substantially vertical axis and acting between said frame and said lever at a locality intermediate the ends of said lever and guiding said lever for movement in a substantially horizontal plane, manual operating members disposed one on each end of said lever and accesible at the ends of the case for swinging said lever from side to side, a rack meshing with said pinion and disposed in a substantially horizontal plane above said lever and extending transversely of said lever, pivot means disposed between said rack and lever and causing longitudinal movement of said rack upon swinging of said lever, said pivot means partially supporting said rack and a keeper engageable with said rack and partially supporting said rack and holding said rack in engagement with said pinion and guiding said rack for longitudinal movement.

13. In a color control for bread toasters having a case, a support at the lower portion thereof and a timing mechanism at one end including a revoluble member with a substantially vertical axis and adapted upon rotation to vary th timing period to vary the color of the toast, said color control device including a pinion rotatable with said revoluble member, a lever disposed below said case and extending from end to end of said case, pivot means for said lever having a substantially vertical axis and acting between said support and said lever at a locality intermediate the ends of said lever and guiding said lever for movement in a substantially horizontal plane, manual operating members disposed one on each end of said lever and accessible at the ends of the case for swinging said lever from side to side, a rack meshing with said pinion and disposed in a substantially horizontal plane abov said lever and extending transversely of said lever, pivot means disposed between said rack and lever and causing longitudinal movement of said rack upon swinging of said lever, and guide means engaging said rack and guiding said rack for longitudinal movement and maintaining said rack in mesh with said pinion.

HENRY L. OLSON. ROBERT A. MILLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 18,923 Harris Aug. 22, 1933 2,237,146 Ireland Apr. 1, 1941 2,337,124 Olving Dec, 21, 1943 2,365,909 Sardeson Dec. 26, 1944 FOREIGN PATENTS Number Country Date 5,538 Great Britain of 1911 

